I don't think he has done everything
Update your BIOS, as you stated you have not done so. It is not that risky
If the Thermometer agrees with CoreTemp then you do need to do something about your chips thermal levels.
Also try downloading and using TAT. See if it agrees with CoreTemp
The easiest way is to purchase a different cooler, as your current cooler may be fault. There is also a chance that the Integrated Heat Spreader is malfunctioning. If this is the case then the CPU is at fault.
The harder way is to modify the voltage chips and MOSFET's. I suggest you don't do that unless you know what you are doing. However you could attempt to create a win tunnel to reduce ambient and core thermals